Drying drum



1,628 481 May l0 1927. J. B. VERNAY DRYING DRUM Filed Nov. 27. 1926 2" c, genees noe ooo non q oo ooo o e c es oe Paten-ted May 10, 1927.l

JEAN BAPTISTE VERNAY, OF VILLEURBANNE, FRANCE.

DRYIN G DRUM.

Application :tiled November 27, 1926, Serial No. 151,088, and in France December 5, 1925.

This invention relates to drying drums for continuous operation. These machines have hitherto comprised an inclined rotatin cylinder, the paste to be dried beine' intro uced 'at the upper end of this cylinler and the -dried powder being taken oii' at the lower one. Vacuum is generallyv used together with heat for effecting the drying. The length of such a machine must be great enough for insuring a' complete drying and a suitably large output. This leads to cumbersome and costly installations. A powerful motor is used for rotating the cylinder and associatedl parts and a considerable l5 amount of heat is lost by radiation.

According to the present invention the drying apparatus is formed by several hollow rotating cylinders, substantially co-axial with each other. The paste to be dried' is introduced at one end of the cylinder having thesmallest` diameter and is discharged at the other end of this cylinder where it falls on the inner surface of the second cylinder and so on, down to the inner surface of the last cylinder from which it falls into a sta-vv tionary device used for the outlet of the dried powder. The apparatus is reduced in length and 'the losses'by radiation are very small.

In the annexed drawing:

Fig. 1 is an axial vertical section. Fig. 2 is a cross-section on line A-A,

Fil.

e apparatus as shown com rises seven a5 rotating co-axial cylinders. Cy inders 1, 2, 3 and 4 are fixed at one end to. a circular plate 5 and annular spaces are left lbetween their other ends and a second circular late 6, to which cylinders 7, 8 and 9 are xed.

Annular spaces are also left between the free ends of cylinders 7, 8 and 9 and plate 5. Plates 5 and 6 are keyed on a hollow shaft 10 provided with radial holes 11. The bore of shaft 10 is connected4 to the vacuum pump not shown) through a packing-gland or the ike. For insuring a sufficient rigiditly, stay-bolts 12 are used -for connecting p ates 5 and 6 together. p

A tube or bar 13 is wound on the inner surface of each cylinder, thus forming a helical guide which isl intended for feeding thle paste towards the annular space at the outer end of the cylinder when the apparatus uis rotated. Hence it follows that two succes- Il sive cylinders have their feed windings or screws inverted.

-The outlet -and 24 which permit the extraction of the outlet vof the air.

Radial holes -are provided in the walls A of the cylinders 1, 2, 3, 7, 8 and 9. The v chine.

A packing gland 19 is provided around shaft 10 which is driven by a pulley 20. Feeding-screw 16 is driven by a ulley 2l and the paste insures by itself a tight closing o f the apparatus'.

A funnel`22 is placed under the last annular space, between plate 6 and cylinder l.

comprises two sliding valves 23 dried matter without breaking the vacuum. Heating is provided b steam pipes 25.

'The apparatus wor s as follows: The paste or other materiall to be dried is introduced into funnel 14 whence it is fed to the .cho ping device 17-18 and then falls into the rst cylinder 1. It travels on the inner Surface of this cylinder under the action of the helical feeder 13 and falls on the inner surface of the second cylinder 7, etc. The dried materialfinally falls into funnel 22. The smaller pieces of material fall directly through the holes of the cylinders to ether with the already dried particles an their travel is shortened.

The ap aratus ma work with hot air by provl ing holes or the inlet and the What I claim is:

1. A drying a paratus comprising in combination a hol ow rotating shaft provided with perforations; two circular plates on said shaft; co-axial cylinders xedto the inner surface of said lates.; and a tight casing vfor permitting rying to take place under vacuum, said shaft adapted to, be

connected with a vacuum pump.

2. A d ing a paratus comprising a rotary set o neste coaxial-cylinders, a chopping device at the inlet end of the innermost cylindenin position for the chop ed material to ..fall therefrom into that cy inder, and means for feeding the material to he dried to said device.

3. A drying apparatus comprising a'rotary shaft, aY pair 'of closure plates fixed thereto in spaced relation, a group of openended coaxial cylinders secured at one end to one plate and terminating short of the other plate, a group of-openended coaxial cylinders'nested within the first group and secured at one e'nd to the second-named plate and terminating short of the first named plate so as to unite with the 'first group in providing a zig-zag passage-Way for the material from cylinder to cylinder, achopping device at the inlet end of ,the innermost cylinder in position for the chopped material to fall therefrom `into that cylinder and embodying a member which is secured to the adjacent plate to rotate therewith, and means for feeding the material toI be dried to said device.

ai. A drying apparatus comprising a perforated rotary shaft adapted to he connected with a source of vacuum, a pair of closure plates fixed to said shaft in spaced relation, a group of open-ended coaxial cylinders secured at one end to one plate and terminating short of the other plate, a group of open-ended coaxial cylinders nested Within the first group and secured at one end to the second-named plate and terminating short of the first-named plate so as to unite with the firstgroup in providing a zig-zag passage-Way for the material from cylinder to cylinder, an air-tight casing enclosing said cylinders and plates, and heating means inside said casing.

5; A drying apparatus comprising a-perforated rotary shaft adapted to be connected with a source of vacuum. a'pair of clo sure plates fixed to said shaft in spaced relation, a group of open-ended coaxial cylinders secured at one end to one plate and terminating short of the other plate, a group of open-ended coaxial cylindersvnested Within the first group and secured at one end to the second-named plate and terminating short of the first-named plate so as to unite with the first group in providing a Zigzag passage-Way for the material from cylinder to cylinder, a chopping device at the inlet end of the innermost cylinder in position for the chop ed material to fall therefrom into that cylinder, means for feeding the material to be dried to sald device, an air-tight casing enclosing said cylinders and plates, and heating means inside said casing. Y

6. A drying apparatus comprising a set ofnested, coaxial cylinders rotatable as a unit, and means for feeding the material to he dried through said cylinders from 'the innermost to vthe outermost in a' zig-zag path; said cylinders having their Walls perforated to permit the passage therethrough of dried particles of material and small pieces of material to he dried, the diameters of the perforations varying according to the diameters of the cylinders themselves, the smallest cylinder having the perforations of greatest diameter, and the largest cylinder being unperforated.

In testimony whereof I afx my signature.

-JEAN BAPTISTE VERNAY. 

